In any relationship , trust is paramount. However, when doubts or feelings of distance arise, many people begin to look for signs that will help them understand what’s happening. In this context, it’s not surprising that the idea of a “key question” emerges, one capable of revealing more than meets the eye. While there’s no foolproof formula for confirming infidelity , psychology and communication experts agree that the way someone responds can offer relevant clues about the state of the relationship.